Images From Refurbished Hubble Pack Visual Punch
Thursday, September 10, 2009
NASA's Hubble Space Telescope, rebuilt by astronauts, has demonstrated its new powers with a stunning set of images of exploding stars, a stellar nursery, colliding galaxies and the lensing effect of a galactic cluster nearly halfway across the universe.
The Hubble was repaired and refurbished earlier this year in a series of tense spacewalks by astronauts on the space shuttle Atlantis, all of whom attended a packed briefing Wednesday morning at NASA headquarters. They fixed two broken instruments and installed a new camera, a spectrograph, new batteries and gyroscopes. Months later, everything appears to be working splendidly.
The agency made sure that the newest Hubble images packed some visual punch. The most dramatic come from the Wide Field Camera 3, which the astronauts installed after a protracted struggle with a stuck bolt that threatened to keep the camera from ever being used.
One image shows planetary nebula NGC 6302, more commonly known as the Butterfly Nebula. It's a dying star ejecting two "wings" of gas. For the past two millennia, the gas has been spreading outward, and the "butterfly" is now trillions of miles in diameter.
"It portends what our solar system is going to look like in about 4 billion years," Edward J. Weiler, NASA's head of science, said in an interview. "We're seeing the sun's death in 4 billion years."
Another image shows a cluster of galaxies known as Stephan's Quintet. Two of the galaxies are melding like fried eggs plopped together in a pan. Two more will eventually join them to form a single colossal galaxy.
The Hubble also made complementary observations, one in optical light and one in infrared light, of a billowing star-forming region in the Carina Nebula, which is about 7,500 light-years from Earth. The optical image shows a glowing pillar of dust. The infrared shot penetrates the dust -- peeling back the curtain, in a sense -- to show what's inside. Four primary stars are baking inside. One, in the center, emits two jets of gas, like a plane with dual vapor trails.
"You see how this gives you new eyes," astrophysicist Mario Livio of the Space Telescope Science Institute said after the briefing. "We see this incredible resolution in the visible and then we see the same thing with the same kind of resolution in the infrared. That blew me away."
Another new Hubble image demonstrates the peculiar effects of gravitational lensing. The newly repaired Advanced Camera for Surveys peered 5 billion light-years across the cosmos at a cluster of galaxies. Their combined gravity acts like a lens to magnify a background galaxy that is so distorted and elongated by the effect that it has taken on a shape that inspired astronomers to call it the "Dragon."
The Hubble was launched in 1990 but initially suffered from an aberration in the primary mirror that left images fuzzy. A repair mission three years later fixed the problem, and four more servicing missions have kept the telescope functioning despite the corrosive environment of low Earth orbit.
No more repair missions are contemplated, however. It is unclear how long the Hubble can function before its instruments, gyroscopes and batteries fail, but NASA hopes to milk it for at least five years.
"We have the birth of a new telescope," Weiler said. "There's no reason this thing can't last at least five years, perhaps as much as 10, with a big emphasis on perhaps. It is a 19-year-old system, after all."